- Alkyloxy modified pyrene fluorophores with tunable photophysical and crystalline properties
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Novel alkyloxy modified 2,7-di-tert-butyl-4,5,9,10-tetra(arylethynyl)pyrenes were prepared through a straightforward Sonogashira coupling approach. Optical properties such as quantum yields and absorption/emission spectra of the fluorophores were investigated by UV/Vis and fluorescence measurements. Aggregation induced excimer formation of the chromophores in polar solvents and in the solid state was proved by the presence of a characteristic bathochromically shifted emission band and a decrease of the emission capability. These results strongly indicate the unexpected observation that the excimer formation of adjacent pyrene rings is not prevented by the introduction of bulky tert-butyl substituents. Single-crystal X-ray and computational analyses reveal the co-planar alignment of adjacent molecules and the presence of π-π-stacking in the molecular packing of the pyrene polyaromatics. Furthermore, fluorescence, DSC and POM measurements indicate that the aggregation behaviour, the thermal characteristics and the crystalline properties are significantly influenced by changing structural features of the attached functional groups at the periphery of the pyrene core.
- Kapf, Andreas,Eslahi, Hassan,Blanke, Meik,Saccone, Marco,Giese, Michael,Albrecht, Marcel
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p. 6361 - 6371
(2019/04/25)
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- Thermal and nonlinear optical studies of newly synthesized EDOT based bent-core and hockey-stick like liquid crystals
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Novel EDOT based bent-core and hockey-stick shaped mesogens bearing terminal alkyl chains and alkoxy terminal chains, respectively, have been designed and synthesized via the Sonogashira coupling reaction. Molecular structures of these new compounds were
- Gowda, Ashwathanarayana,Jacob, Litwin,Joy, Nithin,Philip, Reji,Pratibha,Kumar, Sandeep
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p. 2047 - 2057
(2018/02/09)
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- Ullazine Donor–π bridge-Acceptor Organic Dyes for Dye-Sensitized Solar Cells
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A series of four ullazine-donor based donor–π bridge-acceptor (D–π–A) dyes have been synthesized and compared to a prior ullazine donor-acceptor (D–A) dye as well as a triphenylamine donor with an identical π–bridge and acceptor. The D–π–A ullazine series demonstrates an unusually uniform-in-intensity panchromatic UV/Vis absorption spectrum throughout the visible region. This is in part due to the introduction of strong high-energy bands through incorporation of the ullazine building block as shown by computational analysis. The dyes were characterized on TiO2 films and in DSC devices. Performances of 5.6 % power conversion efficiency were obtained with IPCE onsets reaching 800 nm.
- Zhang, Yanbing,Cheema, Hammad,McNamara, Louis,Hunt, Leigh Anna,Hammer, Nathan I.,Delcamp, Jared H.
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supporting information
p. 5939 - 5949
(2018/03/28)
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- Solid-Solid Phase Transitions in [ trans-Pt(PMe3)2(C=CC6H4R)2]-Containing Materials (R = O(CH2)nH; N = 6, 9, 12, and 15)
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The title complexes were prepared in Hagihara conditions and were investigated by single crystal X-ray crystallography (n = 6, [Pt]C6; n = 12, [Pt]C12), X-ray powder diffraction (powder XRD), differential scanning calorimetry (DSC),
- Marineau Plante, Gabriel,Fortin, Daniel,Soldera, Armand,Harvey, Pierre D.
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p. 2544 - 2552
(2018/08/21)
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- MACROCYCLIC BROAD SPECTRUM ANTIBIOTICS
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Provided herein are antibacterial compounds, wherein the compounds in some embodiments have broad spectrum bioactivity. In various embodiments, the compounds act by inhibition of bacterial type 1 signal peptidase (SpsB), an essential protein in bacteria. Pharmaceutical compositions and methods for treatment using the compounds described herein are also provided.
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Paragraph 00791; 00899
(2018/09/12)
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- Double thiopheneglyoxylic [...] and derivatives and preparation method
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The invention discloses bithienofluorene, its derivative and a preparation method. The compounds are characterized in that: a fluorene ring is in connection with thieno rings, and the 2- position of thiophene has a substituent group, which can be hydrogen, alkyl or aryl. The preparation method consists of: taking 2, 7-dyhydroxyl-9-fluorenone as a raw material, employing sulfonyl chloride to conduct chlorination so as to synthesize 3, 6-dichloro-2, 7-dyhydroxyl-9-fluorenone; and then adopting trifluoromethanesulfonic anhydride to carry out esterification, and performing a Sonogashira coupling reaction to obtain series of 2, 7-disubstituted ethynyl-3, 6-dichloro-9-fluorenone, and finally conducting ring closing by sodium sulfide and reduction to obtain bithienofluorene and its derivative. The series of compounds involved in the invention provides a new option for organic field effect transistor materials, and the preparation method provides a new method for aromatic ketone carbonyl reduction.
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- Fluoranthene derivatives as blue fluorescent materials for non-doped organic light-emitting diodes
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In this study, we report synthesis of symmetrically and non-symmetrically functionalized fluoranthene-based blue fluorescent molecular materials for non-doped electroluminescent devices. The solid state structure of these fluorophores has been established
- Kumar, Shiv,Kumar, Deepak,Patil, Yogesh,Patil, Satish
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p. 193 - 200
(2015/12/30)
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- Arylethynyl-substituted tristriazolotriazines: Synthesis, optical properties, and thermotropic behavior
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The synthesis of C3-symmetrical tristriazolotriazines with conjugated arms and lateral alkoxy side chains was performed by a threefold condensation of cyanuric chloride with tetrazoles. Conjugated π segments include phenyl, tolane, and its phenylethynyl-elongated homologue. Disclike and a dendritic molecule have been obtained, and two compounds with a 3,4,5-tris(octyloxy) substitution form broad thermotropic mesophases. The linear optical properties, solvatochromism of the fluorescence, acidochromism, and the two-photon absorption efficiency of selected compounds are reported. Copyright
- Glang, Stefan,Rieth, Thorsten,Borchmann, Dorothee,Fortunati, Ilaria,Signorini, Raffaella,Detert, Heiner
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p. 3116 - 3126
(2014/06/09)
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- Synthesis of unsymmetrical aryl-ethynylated benzenes via regiocontrolled Sonogashira reaction of 1,3,5-tribromobenzene
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Sonogashira coupling of trimethylsilylacetylene with 4-alkyloxy-1-iodobenzenes gave 2-(4-(alkyloxy)phenyl)ethynyltrimethylsilanes which undergo deprotection via removal of TMS-group using tetrabutylammonium fluoride (TBAF) in THF at room temperature to af
- Dawood, Kamal M.,Hassaneen, Hamdi M.,Abdelhadi, Hyam A.,Ahmed, Mohamed S. M.,Mohamed, Mohamed A.-M.
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p. 1688 - 1695
(2015/01/08)
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- The molecular engineering of organic sensitizers for solar-cell applications
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Positive to the core: Ullazine has both strong electron-donating and weak accepting properties. This heterocycle was incorporated into sensitizers for dye-sensitized solar cells (DSCs). One of these sensitizers demonstrated strong light absorption across the UV/Vis region. The corresponding DSC device has a maximum IPCE of 95% at 520 nm, with a power conversion efficiency of 8.4%.
- Delcamp, Jared H.,Yella, Aswani,Holcombe, Thomas W.,Nazeeruddin, Mohammad K.,Graetzel, Michael
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supporting information
p. 376 - 380
(2013/02/23)
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- Synthesis of diphenyl-diacetylene-based nematic liquid crystals and their high birefringence properties
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We synthesized two series of diphenyl-diacetylene (DPDA)-based materials with alkoxy and alkyl tails of length m (DPDA-OCm and DPDA-Cm, respectively), and measured their nematic-phase birefringence (Δn) as a function of wavelength and temperature. We found that Δn decreases with an increase in m, possibly by a dilution effect of the low-Δn alkyl tail. Further, of the two series, Δn was found to be relatively higher in the DPDA-OCm materials, with the highest value of 0.4 obtained for DPDA-OC1 at 550 nm at 10 °C below the isotropic-to-nematic transition temperature. Further, we observed the temperature dependence for Δn, which is proportional to the order parameter (s). From extrapolation to s = 1 (the perfect orientation state), it is speculated that the DPDA-O moiety has the potential to afford a very large Δn of 0.9. The Royal Society of Chemistry 2012.
- Arakawa, Yuki,Nakajima, Shunpei,Ishige, Ryohei,Uchimura, Makoto,Kang, Sungmin,Konishi, Gen-Ichi,Watanabe, Junji
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p. 8394 - 8398
(2012/07/28)
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- Femtogram detection of explosive nitroaromatics: Fluoranthene-based fluorescent chemosensors
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Herein we report a novel fluoranthene-based fluorescent fluorophore 7,10-bis(4-bromophenyl)-8,9-bis[4-(hexyloxy)phenyl]fluoranthene (S3) and its remarkable properties in applications of explosive detection. The sensitivity towards the detection
- Venkatramaiah,Kumar, Shiv,Patil, Satish
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p. 14745 - 14751
(2013/01/15)
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- Synthesis and electrochemical and theoretical studies of V-shaped donor-acceptor hexaazatriphenylene derivatives for second harmonic generation
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In this article we describe novel synthetic strategies toward well-defined disubstituted conjugated hexaazatriphenylene (HAT) derivatives. The systems are designed as novel V-shaped chromophores displaying C2 symmetry suitable for nonlinear optical investigations. Different donor moieties and linkers have been used in order to tune the electrochemical properties as well as the absorption spectra of the novel HAT derivatives. μβ values as high as 1010 × 10-48 esu have been obtained for a derivative containing the electron-rich dibutylamino moiety. Theoretical calculations have been performed showing a reasonable agreement with the experimental results and supporting the two-dimensional NLO character of these chromophores.
- Juarez, Rafael,Ramos, Mar,Segura, Jose L.,Orduna, Jesus,Villacampa, Belen,Alicante, Raquel
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scheme or table
p. 7542 - 7549
(2011/03/17)
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- N -Heterocyclic donor- and acceptor-type ligands based on 2-(1 H -[1,2,3]Triazol-4-yl)pyridines and their ruthenium(II) complexes
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New 2-(1H-[1,2,3]triazol-4-yl)pyridine bidentate ligands were synthesized as bipyridine analogs, whereas different phenylacetylene moieties of donor and acceptor nature were attached at the 5-position of the pyridine unit. The latter moieties featured a crucial influence on the electronic properties of those ligands. The N-heterocyclic ligands were coordinated to ruthenium(II) metal ions by using a bis(4,4′-dimethyl-2,2′-bipyridine)ruthenium(II) precursor. The donor or acceptor capability of the 2-(1H-[1,2,3]triazol-4-yl) pyridine ligands determined the quantum yield of the resulting ruthenium(II) complexes remarkably. Separately, 2-([1,2,3]triazol-4-yl)pyridine ligands are known to be potential quenchers, but using these new ligand systems led to room temperature emission of the corresponding ruthenium(II) complexes. The compounds have been fully characterized by elemental analysis, high-resolution ESI mass spectrometry, 1H and 13C NMR spectroscopy, and X-ray crystallography. Theoretical calculations for two ruthenium(II) complexes bearing a donor and acceptor unit, respectively, were performed to gain a deeper understanding of the photophysical behavior.
- Happ, Bobby,Escudero, Daniel,Hager, Martin D.,Friebe, Christian,Winter, Andreas,Goerls, Helmar,Altuntas, Esra,Gonzalez, Leticia,Schubert, Ulrich S.
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experimental part
p. 4025 - 4038
(2010/08/06)
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- High birefringence nematic liquid crystals for display and telecom applications
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Several compounds with high birefringence and, having tolane structure were synthesized. For a high polarizability, isothiocyanato (NCS) terminal group was introduced. Another goal of this study was reduction of melting point and smectic phases by introduction of fluorine as lateral substituent. The transition temperatures for all the synthesized compounds and the refractive and dielectric indices for one of the compounds have been determined. Electro-optic (EO) measurements were also performed.
- Catanescu, Carmen Otilia,Chien,Wu, Shin-Tson
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p. 93/[1135]-102/[1144]
(2007/10/03)
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- Specific interactions in discotic liquid crystals
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A series of novel mesogens have been prepared by a five-fold Sonogashira reaction of terminal acetylenes with a functionalized pentabromophenol derivative. The corresponding side-chain substituted polymers were prepared by an analogous polymer substitution reaction. The mesogens differ in the nature of the substituents, i.e. CH2, O, S, SO2 and CONH groups, linking five hexyl tails to the core. A wide range of mesophases and corresponding transition temperatures have been detected, varying from low melting nematic phases to highly stable columnar phases. The wide spread in phase behaviour is described in terms of specific intermolecular interactions. The addition of planar electron deficient molecules resulted in the formation of charge transfer complexes. The observed stabilisation or destabilisation of the mesophases is explained by considering the complexation strength of the complex as well as steric factors.
- Kouwer, Paul H. J.,Jager, Wolter F.,Mijs, Wim J.,Picken, Stephen J.
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p. 458 - 469
(2007/10/03)
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- Synthesis and mesomorphic properties of some fluorinated benzoate liquid crystals
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Three series of [4-(4′-n-alkyloxyphenyl)acetylenyl]-2,6- difluorophenyl fluorinated benezoates and one series of fluorinated benzoates with 2,3,5,6-tetrafluorophenylene group and semi-perfluorocarbon chain have been synthesized. Their phase transition temperatures have been measured by texture observation in a polarizing microscope and confirmed by DSC. For the series without fluorocarbon chains, increasing the quantity of fluorosubstituents on the terminal phenyl groups decreased nematic stability (TN-I), but the breadth of the SmA phase range was increased. Lateral fluorosubstitution in the central group lowered the nematic stability (TN-I) and decreased the breadth of the SmA phase range. The series with semiperfluorocarbon chains were more likely to form SmA phases than the series with hydrogencarbon chains, and with the increasing of fluorosubstituents quantity on the terminal phenyl groups nematic and SmA stability (TN-I and TsmA-N) were both decreased.
- Yang, Yong Gang,Chen,Tang,Wen
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- Solid dimorphism of tetra-arylcyclobutadienecobalt derivatives bearing long aliphatic lateral groups
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A new series of disk-like cyclobutadienecobalt derivatives symmetrically substituted by lateral alkoxy groups with different chain lengths (-O(CH2)nCH3, n=5, 6, 8, and 12) were prepared and their thermal phase transition b
- Yamanishi, Hiroko,Tomita, Ikuyoshi,Ohta, Kazuchika,Endo, Takeshi
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- Synthesis and mesomorphic properties of some fluoro-substituted benzoates
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Several series of fluoro-substituted benzoate liquid crystals have been synthesized. The results showed that the SmA phase is enhanced with the increasing of the degree of fluoro-substitution on the para- and meta-position of the terminal phenyl groups. And the molecules which have same molecular structural formula show nearly the same melting points. It is also discussed about the effect of the ester bond's direction on the mesomorphic properties.
- Yang,Tang,Gong,Wen
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p. 153 - 165
(2007/10/03)
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- The structure and nonlinear optical properties of 3-n-propylamide-4-(4- hexyloxyphenylethynyl)-nitrobenzene
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We have synthesized the tolane derivative 3-n-propylamide-4-(4- hexyloxyphenylethynyl)-nitrobenzene 1 and examined its second-order nonlinear properties and crystal structure. Compound 1 crystallizes in the space group Clc1 with a = 27.667(6), b = 4.910(2), c = 20.856(3) A, β = 128.36(3)°and Z = 4, and shows a high second-order nonlinear optical efficiency. It has an intermolecular hydrogen bond between C=O and N-H in the amide group. This hydrogen bond plays an important role in forming a non-centrosymmetric structure appropriate for nonlinear optical materials.
- Kato, Midori,Kobayashi, Kimiko,Okunaka, Masaaki,Sugita, Nami,Kiguchi, Masashi,Taniguchi, Yoshio
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p. 139 - 143
(2007/10/03)
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- Liquid crystal compounds and optically active compounds
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A compound usefull for liquid crystal component which is represented by the following formulas (1), (2), (3), or (4) ;, R1 -X1 -A1 -( A2 )n-Y1 -A3 -X2 -R2 (1), R1 -X1 -( A3 -Y1 )N-A1 -A2 -X2 -R2 (2), R3 -X1 -A4 -Y1 -A3 -X2 -R4 (3), R3 -X1 -A5 -Y1 -A1 -A2 -X2 -R4 (4), wherein R1 ,R2 ,R3 and R4 are C1 18 alkyl groups; X1 and X2 is -, O, S, -C≡C- or divarent groups such as COO, OCO, CH2 O or OCH2
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